Sorry to hear that Cirrus was so stressed at the vet's . But now that he is home, he can recouperate in comfort.
If the e-collar looks like I believe it looks, you might be able to keep it on with a collar instead of gauze (or other type of ribbon that is tied on) The collar should fit through the loops and it will buckle into place.
Don't stress yourself about his running and jumping, it has been my experience that they pretty much do what they feel like they can do.
Best of luck. The next 2 weeks will go fast.